Liquid crystal antenna, manufacturing method thereof and communication device

ABSTRACT

Provided are a liquid crystal antenna, a manufacturing method thereof and a communication device having the liquid crystal antenna. The liquid crystal antenna includes a first metal electrode, a second metal electrode, a third metal electrode, at least two oppositely arranged substrates, and a liquid crystal layer located between the two oppositely arranged substrates. The two oppositely arranged substrates each include a light transmission area. The first metal electrode, the second metal electrode and the third metal electrode within the light transmission area each are a hollowed-out structure, and the light transmission area can be used to test a cell thickness of the liquid crystal cell. Since the cell thickness can be measured, other process parameters can be matched and adjusted, so that a mass production yield of the liquid crystal antennas is improved.

This application claims priority to Chinese Patent Application No.202011004029.9 filed Sep. 22, 2020, the disclosure of which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present application relates to the technology of communication, inparticular, a liquid crystal antenna, a manufacturing method thereof anda communication device using the liquid crystal antenna.

BACKGROUND

An antenna plays an important role in transmitting and receivingelectromagnetic waves as a radio device. In another word, if there wereno antenna, there would be no radio device. At present, there are manykinds of antennas in the market, such as communication wires, televisionantennas, and radar antennas. With continuous development ofcommunication technology, there is an increasing demand forcommunication with large capacity and high transmission speed.Especially with the advent of the 5G era, the antenna must havedirectivity, so that signal energy can be concentrated in a specificdirection. On one hand, interference to other antenna devices isreduced, and on the other hand, waste of signal energy is reduced,thereby improving communication quality.

A liquid crystal antenna is a kind of antenna using the dielectricanisotropy of the liquid crystal to change magnitude of a phase shift ofa phase shifter by controlling a deflection direction of the liquidcrystal, so as to adjust an alignment direction of a phased arrayantenna. Compared with traditional antennas such as a horn antenna,spiral antenna and array antenna, the liquid crystal antenna hasfeatures such as miniaturization, wide-band, multi-band and high gain.Therefore, the liquid crystal antenna is a kind of antenna more suitablefor current technological development, and has a wide applicationprospect in the fields such as satellite receiving antenna, vehicleradar, and base station antenna.

However, as a newly developed antenna product, the liquid crystalantenna has difficulty in producing a large quantity of products thatmeet performance requirements, and a corresponding yield is very low. Inaddition, liquid crystal antenna products produced in the same batchalso have great differences in performance.

SUMMARY

In view of the above, embodiments of the present disclosure provide anovel liquid crystal antenna and a manufacturing method thereof toimprove a production yield and performance stability of the liquidcrystal antenna.

Firstly, provided is a liquid crystal antenna, including: a firstsubstrate, a second substrate, a liquid crystal layer, a first metalelectrode, a driving circuit, a second metal electrode, a third metalelectrode, and a first frame sealing structure.

The second substrate is arranged opposite to the first substrate.

The liquid crystal layer is located between the first substrate and thesecond substrate.

The first metal electrode is located on one side of the first substratefacing toward the second substrate, and the first metal electrodeincludes a plurality of microstrip line units.

The driving circuit is located within a step area of the first substratebeyond the second substrate, and the first metal electrode iselectrically connected to the driving circuit.

The second metal electrode is located on one side of the secondsubstrate facing toward the first substrate, the second metal electrodeincludes a plurality of hollow-out areas, and a vertical projection ofone of the plurality of hollow-out areas on the second substrate islocated within a vertical projection (i.e., a second projection) of thefirst metal electrode on the second substrate.

The third metal electrode is located on one side of the second substratefacing away from the first substrate, the vertical projection of one ofthe plurality of first hollow-out areas on the second substrate islocated within a vertical projection of the third metal electrode on thesecond substrate.

The first frame sealing structure is located between the first substrateand the second substrate and arranged around the liquid crystal layer,and the first substrate, the second substrate and the first framesealing structure form a liquid crystal cell.

The first substrate and the second substrate each are a transparentsubstrate.

The first substrate includes a first extension area beyond the firstframe sealing structure, the first extension area includes a first lighttransmission area, a first transparent film layer or no structure isarranged within the first light transmission area.

The second substrate includes a second extension area beyond the firstframe sealing structure, the second extension area includes a secondlight transmission area, a second transparent film layer or no structureis arranged within the second light transmission area.

The first light transmission area is overlapped with the second lighttransmission area.

Secondly, provided is another liquid crystal antenna, including: a firstsubstrate, a second substrate, a liquid crystal layer, a first framesealing structure, a first metal electrode, a driving circuit, a secondmetal electrode, and a third metal electrode.

The second substrate is arranged opposite to the first substrate.

The liquid crystal layer is located between the first substrate and thesecond substrate.

The first frame sealing structure is located between the first substrateand the second substrate and arranged around the liquid crystal layer,and the first substrate, the second substrate and the first framesealing structure form a liquid crystal cell.

The first metal electrode is located on one side of the first substratefacing toward the second substrate, and the first metal electrodeincludes a plurality of microstrip line units.

The driving circuit is located within a step area of the first substratebeyond the second substrate, and the first metal electrode iselectrically connected to the driving circuit.

The second metal electrode is located on one side of the secondsubstrate facing toward the first substrate, the second metal electrodeincludes a plurality of first hollow-out areas and at least one thirdhollow-out area, and a vertical projection of one of the plurality offirst hollow-out areas on the second substrate is located within avertical projection of the second metal electrode on the secondsubstrate.

The third metal electrode is located on one side of the second substratefacing away from the first substrate, the vertical projection of the oneof the plurality of first hollow-out areas on the second substrate islocated within a vertical projection of the third metal electrode on thesecond substrate.

The at least one third hollow-out area is not overlapped with neitherthe first metal electrode nor the third metal electrode.

The vertical projection of the one of the plurality of first hollow-outareas and a vertical projection of the at least one third hollow-outarea on the second substrate are located within a vertical projection ofthe liquid crystal cell on the second substrate.

Thirdly, further provided is a manufacturing method for the liquidcrystal antenna, including the following steps.

A first substrate and a second substrate are provided, and a first metalelectrode, a line connected to a driving circuit and a first lighttransmission area are formed on the first substrate, where the firstmetal electrode includes a plurality of microstrip line units.

A second metal electrode is formed on one side of the second substrateand a second light transmission area is formed within an area of thesecond substrate beyond the first frame sealing structure, where thesecond metal electrode includes a plurality of first hollow-out areas.

A third metal electrode is formed on another side of the secondsubstrate, where a vertical projection of one of the plurality of firsthollow-out areas on the second substrate is located within a verticalprojection of the third metal electrode on the second substrate, and thethird metal electrode is not overlapped with the second lighttransmission area.

The first substrate formed with the first metal electrode, the lineconnected to the driving circuit and the first light transmission areaand the second substrate formed with the second metal electrode, thesecond light transmission area and the third metal electrode are alignedinto a cell to form a liquid crystal cell, so that a first frame sealingstructure and a liquid crystal layer are arranged between the firstsubstrate and the second substrate, where the first frame sealingstructure is arranged around the liquid crystal layer, and the firstlight transmission area is overlapped with the second light transmissionarea.

The second substrate is cut, so that the first substrate exposes theline connected to the driving circuit.

Fourthly, further provided is another manufacturing method for a liquidcrystal antenna, including the following steps.

A first substrate, a second substrate and a third substrate areprovided, and a first metal electrode, a line connected to a drivingcircuit and a first light transmission area are formed on the firstsubstrate, where the first metal electrode includes a plurality ofmicrostrip line units.

A second metal electrode is formed on one side of the second substrateand a second light transmission area is formed within an area of thesecond substrate beyond the first frame sealing structure, where thesecond metal electrode includes a plurality of first hollow-out areas.

A third metal electrode is formed on one side of the third substrate.

The first substrate formed with the first metal electrode, the lineconnected to the driving circuit and the first light transmission areaand the second substrate formed with the second metal electrode and thesecond light transmission area are aligned into a cell to form a liquidcrystal cell, so that a first frame sealing structure and a liquidcrystal layer are arranged between the first substrate and the secondsubstrate, where the first frame sealing structure is arranged aroundthe liquid crystal layer, and the first light transmission area isoverlapped with the second light transmission area.

The second substrate is cut, so that the first substrate exposes theline connected to the driving circuit.

The third substrate formed with the third metal electrode is aligned andfitted with the liquid crystal cell, so that an area of the thirdsubstrate overlapped with the first light transmission area and thesecond light transmission area is light transmissive.

Finally, further provided is still another manufacturing method for aliquid crystal antenna, including the following steps.

A first substrate and a second substrate are provided, and a first metalelectrode, and a line connected to a driving circuit are formed on thefirst substrate, where the first metal electrode comprises a pluralityof microstrip line units.

A second metal electrode is formed on one side of the second substrate,where the second metal electrode includes a plurality of firsthollow-out areas and at least one third hollow-out area.

A third metal electrode is formed on another side of the secondsubstrate, where a vertical projection of one of the plurality of firsthollow-out areas on the second substrate is located within a verticalprojection of the third metal electrode on the second substrate, and thethird metal electrode is not overlapped with the third lighttransmission area.

The first substrate formed with the first metal electrode and the lineconnected to the driving circuit and the second substrate formed withthe second metal electrode and the third metal electrode are alignedinto a cell to form a liquid crystal cell, so that a first frame sealingstructure and a liquid crystal layer are arranged between the firstsubstrate and the second substrate, where the first frame sealingstructure is arranged around the liquid crystal layer, and the at leastone third hollow-out area is not overlapped with the first metalelectrode.

The second substrate is cut, so that the first substrate exposes theline connected to the driving circuit.

Compared with the liquid crystal antenna in the related art, the liquidcrystal antenna and the manufacturing method thereof provided inembodiments of the present disclosure has the following beneficialeffects.

More qualified liquid crystal antennas can be selected by changing thestructure of the liquid crystal antenna in the related art, orcorresponding matching signals, etc. can be adjusted according to cellthickness parameters. On one hand, one substrate is separately extended,so that the one substrate outside a functional area of the antenna isarranged opposite to an area of the other substrate where no metal layeris provided, and the cell thickness can be measured through thestructure. On the other hand, the oppositely arranged substrate iscapable of realizing cell thickness measurement at a hollow-outareaed-out place by reasonably hollow-out areaing out part of the metallayer.

BRIEF DESCRIPTION OF DRAWINGS

To illustrate the solutions in the embodiments of the present disclosureor the solutions in the related art more clearly, drawings used in thedescription of the embodiments or the related art will be brieflydescribed below. Apparently, the drawings described below are merelyembodiments of the present disclosure, and those skilled in the art mayobtain other drawings based on the provided drawings on the premise thatno creative work is done.

FIG. 1 is a structural diagram illustrating a liquid crystal antenna inthe related art;

FIG. 2 is a sectional diagram taken along AA′ of FIG. 1;

FIG. 3 is a sectional diagram taken along BB′ of FIG. 1;

FIG. 4 is a structural diagram illustrating a liquid crystal antennaaccording to an embodiment of the present application;

FIG. 5 is a sectional diagram taken along CC′ of FIG. 4;

FIG. 6 is another sectional diagram taken along CC′ of FIG. 4;

FIG. 7 is still another sectional diagram taken along CC′ of FIG. 4;

FIG. 8 is a sectional diagram taken along DD′ of FIG. 4;

FIG. 9 is a sectional diagram taken along EE′ of FIG. 4;

FIG. 10 is a structural diagram illustrating another liquid crystalantenna according to an embodiment of the present application;

FIG. 11 is a sectional diagram taken along FF′ of FIG. 10;

FIG. 12 is a sectional diagram taken along GG′ of FIG. 10;

FIG. 13 is a structural diagram illustrating still another liquidcrystal antenna according to an embodiment of the present application;

FIG. 14 is another sectional diagram taken along FF′ of FIG. 10;

FIG. 15 is a structural diagram illustrating still another liquidcrystal antenna according to an embodiment of the present application;

FIG. 16 is another sectional diagram taken along GG′ of FIG. 15;

FIG. 17 is a structural diagram illustrating still another liquidcrystal antenna according to an embodiment of the present application;

FIG. 18 is a structural diagram illustrating still another liquidcrystal antenna according to an embodiment of the present application;

FIG. 19 is a sectional diagram taken along II′ of FIG. 18;

FIG. 20 is another sectional diagram taken along II′ of FIG. 18;

FIG. 21 is a sectional diagram taken along JJ′ of FIG. 18;

FIG. 22 is still another sectional diagram taken along II′ of FIG. 18;

FIG. 23 is a structural diagram illustrating still another liquidcrystal antenna according to an embodiment of the present application;

FIG. 24 is a structural diagram illustrating still another liquidcrystal antenna according to an embodiment of the present application;

FIG. 25 is a sectional diagram taken along KK′ of FIG. 18;

FIG. 26 is a structural diagram illustrating still another liquidcrystal antenna according to an embodiment of the present application;

FIG. 27 is a structural diagram illustrating still another liquidcrystal antenna according to an embodiment of the present application;

FIG. 28 is a structural diagram illustrating still another liquidcrystal antenna according to an embodiment of the present application;

FIG. 29 is a structural diagram illustrating still another liquidcrystal antenna according to an embodiment of the present application;

FIG. 30 is a structural diagram illustrating a communication deviceaccording to an embodiment of the present application;

FIG. 31 is a flow chart illustrating a manufacturing method for a liquidcrystal antenna according to an embodiment of the present application;

FIGS. 32 to 35 are structural diagrams illustrating an intermediateprocess of the manufacturing method for the liquid crystal antennaaccording to an embodiment of the present application;

FIG. 36 is a structural diagram illustrating an intermediate process ofanother manufacturing method for a liquid crystal antenna according toan embodiment of the present application;

FIG. 37 is a flow chart illustrating another manufacturing method for aliquid crystal antenna according to an embodiment of the presentapplication;

FIG. 38 is a flow chart illustrating still another manufacturing methodfor a liquid crystal antenna according to an embodiment of the presentapplication; and

FIGS. 39 to 42 are structural diagrams illustrating still anothermanufacturing method for a liquid crystal antenna according to anembodiment of the present application.

DETAILED DESCRIPTION

The solutions in the embodiments of the present disclosure will bedescribed clearly and completely in conjunction with the drawings in theembodiments of the present disclosure. Apparently, the embodimentsdescribed are part, not all, of the embodiments of the presentdisclosure. Based on the embodiments of the present disclosure, allother embodiments obtained by those skilled in the art without creativework are within the scope of the present disclosure.

Embodiments in this Description are described in a progressive manner.Each embodiment focuses on differences from other embodiments. The sameor similar parts in each embodiment can be referred to by each other. Asfor the device disclosed in the embodiment, since corresponding to themethod disclosed in the embodiment, description of the device isrelatively simple, and the relevant part may refer to the description ofthe method.

Please refer to FIGS. 1 to 3. FIG. 1 is a structural diagramillustrating a liquid crystal antenna in the related art. FIG. 2 is asectional diagram taken along AA of FIG. 1. FIG. 3 is a sectionaldiagram taken along BB′ of FIG. 1. One of liquid crystal antennas in therelated art includes a first substrate 10, a second substrate 20opposite to the first substrate 10, and a liquid crystal layer 30located between the first substrate 10 and the second substrate 20. Thefirst substrate 10 is provided with a microstrip line unit 11, and thesecond substrate 20 is provided with a ground electrode 21 and aradiator electrode 22. A high frequency signal is introduced into theliquid crystal antenna by drilling. Specifically, as shown in FIGS. 1and 3, a through hole 20 h running through the second substrate 20 isarranged on one side of the second substrate 20 beyond the firstsubstrate 10, a metal rod 40 provides a high frequency signal to theliquid crystal antenna through the through hole 20 h, and the highfrequency signal transmits a signal outward under the control of themicrostrip line unit 11, the ground electrode 21 and the radiatorelectrode 22.

However, it is difficult to achieve mass production of the liquidcrystal antennas in the related art. Even for thousands of liquidcrystal antenna products produced in a same batch, only a few of themcan barely meet performance requirements at present, which is bound tolead to extremely low production yield and high production cost, makingit impossible to commercialize the liquid crystal antennas, therebyhindering wide use of the liquid crystal antennas. Research anddevelopment personnels of the present application found that thicknessof a liquid crystal cell of the liquid crystal antenna has a greatinfluence on performance of the antenna. However, even if the influenceof the cell thickness is taken into account in design, and the cellthickness and the frequency of the high frequency signal, a shape andthickness of the microstrip line unit, and a position of the radiatorelectrode, etc. are best matched in a design stage, products producedare still difficult to meet the performance requirements.

Further, the research and development personnel of the presentapplication further found that because control of the thickness of theliquid crystal cell needs to control an amount of liquid crystaldripping during alignment in forming the cell and pressure of pressurehead after an initial cell is formed, the control of the amount ofliquid crystal currently has an error range in a process, and an errorrange of the cell thickness caused by this error range of the amount ofliquid crystal has already led to great differences in the performanceof the liquid crystal antenna. For example, there has been an order ofmagnitude difference in an amount of signal radiation. On the otherhand, there is also a certain error in a magnitude of the pressure ofthe pressure head, which eventually leads to great difficulties in massproduction of the liquid crystal antennas that meet a performancestandard, making it difficult to replace traditional antennas.

On this basis, after studying structures of the liquid crystal antennasin the related art, the research and development personnel of thepresent application found that, in the structure of the liquid crystalantenna, the radiator electrode 22 and the microstrip line unit 11 arearranged at a slit of the ground electrode 21. Therefore, there is noplace where the cell thickness can be measured at a position of theliquid crystal cell. Therefore, in order to solve the above problems,the research and development personnels of the present application cancarry out measurement of the cell thickness by setting a lighttransmission area in the liquid crystal cell; or a surrounding area ofthe liquid crystal cell is specially designed to simulate the liquidcrystal cell, so that the cell thickness of the liquid crystal cell isdetermined by testing the cell thickness of the surrounding area.Hereinafter, the present application will be described through somespecific embodiments.

In an embodiment, provided is a novel liquid crystal antenna. Pleaserefer to FIGS. 4 and 5, FIG. 4 is a structural diagram illustrating theliquid crystal antenna according to an embodiment of the presentapplication. FIG. 5 is a sectional diagram taken along CC′ of FIG. 4.The liquid crystal antenna includes a first substrate 100, a secondsubstrate 200, a liquid crystal layer 300, a first metal electrode 111,a first frame sealing structure 400, a second metal electrode 211, athird metal electrode 222, and a driving circuit 130. The firstsubstrate 100 is oppositely arranged to the second substrate 200. Theliquid crystal layer 300 is located between the first substrate 100 andthe second substrate 200. The first metal electrode 111 is located onone side of the first substrate 100 facing toward the second substrate200, and the first metal electrode 111 includes a plurality ofmicrostrip line units 113. The driving circuit 130 is located in a steparea 101 of the first substrate 100 beyond the second substrate 200, andthe first metal electrode 111 is electrically connected to the drivingcircuit 130. The second metal electrode 211 is located on one side ofthe second substrate 200 facing toward the first substrate 100, thesecond metal electrode 211 includes a plurality of first hollow-outareas 212, and a vertical projection of one of the plurality of firsthollow-out areas 212 on the second substrate 200 is located within avertical projection of the first metal electrode 111 on the secondsubstrate 200. The third metal electrode 222 is located on one side ofthe second substrate 200 facing away from the first substrate 100, andthe vertical projection of the one of the plurality of the firsthollow-out areas 212 on the second substrate 200 is located within avertical projection of the third metal electrode 222 on the secondsubstrate 200. The first frame sealing structure 400 is located betweenthe first substrate 100 and the second substrate 200 and arranged aroundthe liquid crystal layer 300, and the first substrate 100, the secondsubstrate 200 and the first frame sealing structure 400 form a liquidcrystal cell. The first substrate 100 and the second substrate 200 aretransparent substrates. The first substrate 100 includes a firstextension area beyond the first frame sealing structure 400. The firstextension area includes a first light transmission area T1, and thefirst light transmission area T1 is provided with no structure or thefirst light transmission area T1 is provided with a transparent filmlayer. For example, the first light transmission area T1 is providedwith a transparent insulating film, including but not limited to siliconnitride, silicon oxide, organic insulating film, etc.

The second substrate 200 includes a second extension area beyond thefirst frame sealing structure 400, the second extension area includes asecond light transmission area T2, and the second light transmissionarea T2 is provided with no structure or the second light transmissionarea T2 is provided with a transparent film layer. A vertical projectionof the first light transmission area T1 is overlapped with a verticalprojection of the second light transmission area 12. In an embodiment,the first hollow-out area 212 is covered by the third metal electrode222 and is located within a range of the first metal electrode 111. Thesecond light transmission area T2 is provided with no structure or thesecond light transmission area T2 is provided with a transparent filmlayer. For example, the second light transmission area T2 is providedwith is provided with the transparent insulating film, including but notlimited to silicon nitride, silicon oxide, organic insulating film, etc.

Please continue to refer to FIGS. 4 and 5, in an embodiment, the firstsubstrate 100 and the second substrate 200 may be a glass substrate or apolymer substrate, for example, a plastic substrate. Specific materialsof the first substrate 100 and the second substrate 200 are not limitedherein, as long as the first substrate 100 and the second substrate 200are transparent substrates. Apparently, taking production cost,manufacturing process and transmittance requirements into account, thefirst substrate 100 and the second substrate 200 are preferably glasssubstrates.

In the embodiment of the present application, due to overlap of thevertical projection of the first transmission area T1 and the verticalprojection of the second transmission area T2, light can pass through asandwiched area 213 formed between the first transmission area T1 andthe second transmission area T2, and the sandwiched area 213 can performmeasurement of the cell thickness by an optical measurement method.Although the sandwiched area 213 formed between the first lighttransmission area T1 and the second light transmission area T2 is not aliquid crystal cell area, since the first light transmission area T1 islocated within the first substrate 100 and the second transmission area12 is located within the second substrate 200, a cell thickness of theliquid crystal cell is supposed to be H1, a distance between the firstsubstrate 100 and the second substrate 200 is supposed to be H2, athickness sum of film layers formed on a surface of the first substrate100 and located on one side of the first substrate 100 facing toward thesecond substrate 200 is supposed to be H3, and a thickness sum of filmlayers formed on a surface of the second substrate 200 and located onone side of the second substrate facing toward the first substrate 100is supposed to be H4, then H1=H2−(H3+H4). Therefore, when oppositesurfaces of the first substrate 100 and the second substrate 200 thatare arranged at corresponding positions of the first light transmissionarea T1 and the second light transmission area T2 are not provided withthe film layers, a thickness L of the sandwiched area 213 formed betweenthe first light transmission area T1 and the second light transmissionarea T2 is equal to the distance 112 between the first substrate 100 andthe second substrate 200, and the thickness sum H3 of the film layersformed on the surface of the first substrate 100 can be measured orcalculated during cell forming. Similarly, the thickness sum of the filmlayers formed on the surface of the second substrate 200 can be measuredor calculated between forming cells, so that H1 can be determined merelyby determining H2.

If the cell thickness of the liquid crystal cell of the liquid crystalantenna can be measured by the optical measurement method, the cellthickness can be measured after the first substrate 100 and the secondsubstrate 200 are initially fitted in a process of production. If ameasured cell thickness is within a preset range, pressure of a pressurehead can be adjusted to ensure that a final cell thickness of a finalproduced liquid crystal antenna can meet the requirements. In addition,if the final produced liquid crystal antenna fails to meet therequirements in terms of performance, it can also be confirmed by theoptical measurement method whether this is caused by a case where thecell thickness of the liquid crystal cell is not within a reasonablerange, thereby further improving the production yield of the liquidcrystal antenna.

In an embodiment, the liquid crystal antenna further includes a secondframe sealing structure. In an exemplary embodiment, please refer toFIGS. 4 and 6, the liquid crystal antenna further includes a secondframe sealing structure 401. The second frame sealing structure 401 islocated on one side of the first frame sealing structure 400, and thefirst substrate 100, the second substrate 200, the second frame sealingstructure 401 and the first frame sealing structure 400 form anextension cell. In another exemplary embodiment, the second framesealing structure 401 is located on one side of the first frame sealingstructure 400, and the second frame sealing structure 401 and the firstframe sealing structure 400 together form a closed shape. By setting theextension cell, areas of the first substrate 100 and the secondsubstrate 200 beyond the liquid crystal cell are also supported by thesecond frame sealing structure 401, thereby further ensuring that adistance between the first substrate 100 and the second substrate 200and at the sandwiched area formed between the first light transmissionarea T1 and the second light transmission area T2 does not changecompared with the liquid crystal cell area, thereby improving accuracyof the measurement of the cell thickness of the liquid crystal cell.

In an embodiment, the first frame sealing structure 400 and the secondframe sealing structure 401 each are frame sealant. The frame sealant isviscous, has strong plasticity under a normal condition, and hasmechanical properties when cured by light or other means. Therefore,liquid crystal leakage can be prevented by the frame sealant arrangedbetween the first substrate 100 and the second substrate 200, andmeantime, the cell thickness is maintained. When the first frame sealingstructure 400 and the second frame sealing structure 401 are made of asame material, for example, both are made of the frame sealant, thepressure of the pressure head can be adjusted based on the samerelevance to avoid increasing the production cost. In an exemplaryembodiment, different materials change differently under a samepressure. In order to obtain a target cell thickness, it is necessary tomaster a relationship between the pressure and the volume change of anobject under pressure.

In an embodiment, the first frame sealing structure 400 is the framesealant and the second frame sealing structure 401 is a supportingretaining wall. In an exemplary embodiment, please refer to FIGS. 7 and8, a supporting column 230 is arranged in the liquid crystal cell of theliquid crystal antenna, and the supporting column 230 is formed on oneside of the second substrate 200 facing toward the first substrate 100.In another embodiment, the supporting column 230 is formed by a filmforming and lithography process. When the second frame sealing structure401 is the supporting retaining wall, the second sealing frame 401 andthe supporting column 230 can be made of a same material andmanufactured through a same process, thereby avoiding additionalmanufacturing steps.

Combined with structures illustrated in FIGS. 4, 7 and 8, the supportingcolumns 230 may be arranged within gaps between the plurality ofmicrostrip line units 113. In practice, density of the supportingcolumns 230 can be set as needed, thereby increasing a support forcebetween the first substrate 100 and the second substrate 200 andensuring the cell thickness of the liquid crystal cell.

In an embodiment, referring to FIG. 4, the first light transmission areaT1 and the step area 101 are located on a same side of the liquidcrystal cell. The step area 101 is an area of the first substrate 100beyond the second substrate 200. The step area 101 is provided with thedriving circuit 130. The driving circuit 130 is electrically connectedto a binding pad 112 located on the step area 101. The binding pad 112is connected to the microstrip line units 113 by a wire (not shown inFIG. 4). Therefore, besides the area where the wire connecting thebinding pad 112 with the microstrip line unit 113 is arranged, the steparea 101 is also provided with an area where no wire is arranged, andthe area where no wire is arranged can be used as the first lighttransmission area T1 to avoid widening a frame of the liquid crystalantenna, thereby capable of maintaining an advantage of the liquidcrystal antennas that are smaller than traditional ones. Moreover, avertical projection of the second substrate 200 on the first substrate100 is extended to partially overlap with the step area 101, so that thevertical projection of the second light transmission area T2 and thevertical projection of the first light transmission area T1 can overlapto form a light transmission area 213. It is worth noting that even thesecond substrate 200 is extended to overlap with the step area 101 ofthe first substrate 100, the area of the step area 101 of the firstsubstrate 100 where a vertical projection of the binding pad 112 on thefirst substrate 100 is arranged cannot overlap with the verticalprojection of the second substrate 200 on the first substrate 100, so asto be bound with the driving circuit 130.

Please continue to refer to FIG. 4, in an embodiment, the liquid crystalantenna further includes a signal introduction area of the secondsubstrate 200 beyond the first substrate 100. The second metal electrode211 further includes a second hollow-out area 214, and the signalintroduction area is located within the second hollow-out area 214. Athrough hole running through the second substrate 200 is arranged withinthe signal introduction area, and a signal introduction rod 240 passesthrough the through hole to transmit a high frequency signal to theliquid crystal antenna. The liquid crystal antenna is introduced withthe signal through the signal introduction rod 240 and radiates thesignal outward.

In an embodiment, the signal introduction area and the step area 101 arerespectively located on both sides of the liquid crystal cell and areoppositely arranged. Referring to FIG. 9, the signal introduction areais located on a left side of the liquid crystal cell, and the step area101 is located on a right side of the liquid crystal cell. The signalintroduction area and the step area 101 are respectively arranged on twoopposite sides of the liquid crystal cell, so that the signalintroduction area of the second substrate 200 can be perforated, and thedriving circuit can be bound to the first substrate 100.

In the above embodiments provided in the present application, the secondsubstrate 200 is extended to overlap with the step area 101 of the firstsubstrate 100. However, embodiments provided in the present applicationare not limited to this. In an embodiment, please refer to FIGS. 10 to12, the second light transmission area T2 and the signal introductionarea are located on a same side of the liquid crystal cell. The signalintroduction area is provided with the signal introduction rod 240. Thatis, the second light transmission area T2 and the signal introductionrod 240 are located on a same side of the liquid crystal cell. In therelated art, the signal introduction rod is arranged on one side of thesecond substrate 200 beyond the first substrate 100 by perforating, andthe ground electrode is hollow-out areaed out in an area where thesignal introduction rod is located. However, in the embodiments providedin the present application, compared with the liquid crystal antennas inthe related art, the second metal electrode 211 is provided with alarger hollow-out area in an area of the second substrate 200 beyond theliquid crystal cell. Referring to FIG. 10, in the embodiment provided bythe present application, the area of the second substrate 200 beyond theliquid crystal cell is provided with a hollow-out area, that is, thesecond light transmission area T2. The second hollow-out area 214 in thesecond light transmission area T2 as shown in FIG. 10 corresponds to thesignal introduction area of the liquid crystal antenna in the relatedart. Therefore, in the above-mentioned method provided by the embodimentof the present application, the second hollow-out area 214 and thesecond light transmission area T2 are formed in a same productionprocess without increasing the production cost. In addition, since thesecond light transmission area T2 is much larger than the secondhollow-out area 214, it is easier to align to a position of a feederline when perforating, thereby improving the production yield of theliquid crystal antenna.

In the above-mentioned embodiment, the first substrate 100 is extendedto overlap with one side of the second substrate 200 where the signalintroduction rod 240 is arranged, and a transparent area is arranged insuch overlap area to realize the measurement of the cell thickness. Asshown in FIG. 10, the first light transmission area T1 extending outfrom the first substrate 100 is not overlapped with the verticalprojection of the signal introduction area on the first substrate 100.In an exemplary embodiment, supposing that a connection line between thesignal introduction area and the step area 101 is parallel to a firstdirection, the first direction is parallel to a first side of the liquidcrystal antenna, and in a direction perpendicular to the first side, thefirst light transmission area T1 extending out from the first substrate100 is located on both sides of the signal introduction area, so as toperforate in the signal introduction area to allow the signalintroduction rod to pass through.

As illustrated in FIG. 13, in the liquid crystal antenna provided by anembodiment of the present application, the driving circuit 130 is aflexible circuit board. Because of its flexibility, the flexible circuitboard can be connected to other driving members by bending or otherways. Apparently, the embodiments of the present application are notlimited to this. In an embodiment, the driving circuit 130 may be adriving chip. The driving chip is capable of communicating with otherelectronic devices through the flexible circuit board. Apparently, theflexible circuit board illustrated in FIG. 13 is directly connected tothe binding pad 112 on the first substrate 100, or the driving chip canbe first bound to the flexible circuit board, and then the flexiblecircuit board is connected to the binding pad 112.

In the above-mentioned embodiment of the present application, the secondmetal electrode 211 and the third metal electrode 222 are respectivelyarranged on both sides of a same substrate. In other embodiments of thepresent application, the second metal electrode 211 and the third metalelectrode 222 can also be arranged on different substrates. In anexemplary embodiment, please refer to FIG. 14, the liquid crystalantenna further includes a third substrate 200′. The third substrate200′ is located on one side of the second substrate 200 facing away fromthe first substrate 100. The third metal electrode 222 is located on oneside of the third substrate 200′ facing away from the second substrate200. An area of the third substrate 200′ overlapping with verticalprojections of the first light transmission area T1 and second lighttransmission area T2 on the third substrate 200′ is light transmissive.In the present embodiment, since the second metal electrode 211 isarranged on the second substrate 200 and the third metal electrode 222is arranged on the third substrate 200′, double-sided fabrication of apatterned conductive structure on a same substrate is avoided, therebyreducing process difficulty.

In the related art, although a method of fabricating patternedconductive structures on both sides of a same substrate is theoreticallyfeasible, complex processing steps are often needed in practice. Forexample, after fabricating one conductive structure on a first side, ifanother conductive structure on a second side needs to be fabricated,the one conductive structure that has been fabricated on the first sideneeds to be protected in advance, otherwise the one conductive structurefabricated on the first side will be broken when the other conductivestructure is fabricated on the second side.

Illustrated in FIGS. 4 to 14, part of the liquid crystal antenna isomitted. In order to further clearly describe the liquid crystal antennaprovided by the embodiment of the present application, please furtherrefer to FIGS. 15 and 16. In an embodiment, one of the wires 114 forconnecting one of the binding pads 112 with one of the microstrip lineunits 113 is further arranged on the first substrate 100. The wires 114connected to the respective microstrip line units 113 are insulated fromeach other and connected to the different binding pads 112. The secondsubstrate 200 is provided with a feeder line 241 electrically connectedto the signal introduction rod 240. The feeder line 241 is distributedin a dendritic shape and includes a plurality of branches, and avertical projection of one branch of the feeder line 241 on the secondsubstrate 200 partially overlaps with a vertical projection of onemicrostrip line unit 113 on the second substrate 200. The feeder line241 couples the high frequency signal of the signal introduction rod 240to the microstrip line unit 113, and the signal transmitted in themicrostrip line unit 113 is controlled by controlling deflection of theliquid crystal layer 300. Finally, the signal is coupled to the thirdmetal electrode 222 at the first hollow-out area 212 of the second metalelectrode 211, and the third metal electrode 222 radiates the signaloutward. It should be noted that the third metal electrode 222 is aplurality of radiator units independent from each other, and eachradiator unit radiates signals outward.

In an embodiment, the third metal electrode 222 and the feeder line 241are arranged in the same layer, that is, formed by the same process. Inan exemplary embodiment, when a metal film layer is deposited on thesecond substrate 200, the third metal electrode 222 and the feeder line241 are etched at the same time using a same mask plate. In anotherembodiment, the first metal electrode 111 and the wire 114 are arrangedin a same layer. The first metal electrode 111 and the wire 114 areinsulated from each other.

In an embodiment, a vertical projection of the light transmission area213 on the first substrate 100 is not overlapped with neither a verticalprojection of the first metal electrode 111 on the first substrate 100nor a vertical projection of the wire 114 on the first substrate 100,avoiding the overlap of the vertical projection of the metal and thevertical projection of the light transmission area 213 to affect a cellthickness test. In an exemplary embodiment, the light transmission area213 is arranged on both sides of each binding pad 112. Since no othermetal structures are arranged on both sides of the binding pad 112, thecell thickness can be measured using such area of the first substrate100, thereby improving the production yield of the liquid crystalantenna.

It should be noted that in the above drawings, although a shape of thelight transmission area 213 is rectangular, the liquid crystal antennaprovided by the embodiment of the present application is not limited tothis, and the shape of the light transmission area 213 may also besquare, circular, oval, polygonal, etc. In an exemplary embodiment, withreference to FIG. 17, the light transmission area 213 may be across-shaped structure, at the same time, the cross-shaped structure canbe used as an alignment mark to align the first substrate 100 and thesecond substrate 200 to get fitted.

On the other hand, further provided is another type of liquid crystalantenna capable of measuring the cell thickness. In an embodiment,please refer to FIGS. 18 to 20, the liquid crystal antenna includes afirst substrate 100, a second substrate 200, a liquid crystal layer 300,a first frame sealing structure 400, a first metal electrode 111, adriving circuit 130, a second metal electrode 211, and a third metalelectrode 222. The first substrate 100 is oppositely arranged to thesecond substrate 200. The liquid crystal layer 300 is located betweenthe first substrate 100 and the second substrate 200. The first framesealing structure 400 is located between the first substrate 100 and thesecond substrate 200 and arranged around the liquid crystal layer 300,and the first substrate 100, the second substrate 200 and the firstframe sealing structure 400 form a liquid crystal cell. The first metalelectrode 111 is located on one side of the first substrate 100 facingtoward the second substrate 200, and the first metal electrode 111includes a plurality of microstrip line units 113. The driving circuit130 is located within a step area 101 of the first substrate 100 beyondthe second substrate 200, and the first metal electrode 111 iselectrically connected to the driving circuit 130. The second metalelectrode 211 is located on one side of the second substrate 200 facingtoward the first substrate 100. The second metal electrode 211 includesa plurality of first hollow-out areas 212 and at least one thirdhollow-out area 215, and a vertical projection of one of the pluralityof first hollow-out areas 212 on the second substrate 200 is locatedwithin a vertical projection of the first metal electrode 111 on thesecond substrate 200. The third metal electrode 222 is located on oneside of the second substrate 200 facing away from the first substrate100, and the vertical projection of the one of the plurality of thefirst hollow-out areas 212 on the second substrate 200 is located withina vertical projection of the third metal electrode 222 on the secondsubstrate 200. A vertical projection of the third hollow-out area 215 onthe first substrate 100 is not overlapped with neither the verticalprojection of the first metal electrode 111 on the first substrate 100nor the vertical projection of the third metal electrode 222 on thefirst substrate 100. The vertical projection of the first hollow-outarea 212 and the vertical projection of the third hollow-out area 215 onthe second substrate 200 are located within a vertical projection of theliquid crystal cell on the second substrate 200. In an exemplaryembodiment, the first hollow-out area 212 is covered by the third metalelectrode 222 and is located within a range of the first metal electrode111.

In these methods provided by the embodiment of the present application,the first substrate 100 in the liquid crystal cell includes, in additionto the area where the first metal electrode 111 is located, the firstlight transmission area T1 without the first metal electrode 111. Sincethe second substrate within an area merely provided with the secondmetal electrode 211 is provided with the third hollow-out area 215 andthe third hollow-out area 215 corresponds to a transparent area of thesecond substrate 200, that is, the second light transmission area T2,the sandwiched area 213 formed between the first light transmission areaT1 and the second light transmission area T2 forms a light transmissionarea of the liquid crystal cell. In the above embodiment, due toexistence of the light transmission area, the cell thickness test of theliquid crystal cell can be realized, thereby improving the productionyield of the liquid crystal antenna.

In an embodiment, with continued reference to FIGS. 18 and 20, theliquid crystal antenna further includes an annular barrier 500 locatedin the liquid crystal layer 300, and an area surrounded by the annularbarrier 500 overlaps with the third hollow-out area 215. The liquidcrystal layer 300 can be separated by arranging the annular barrier 500,so that liquid crystal molecules cannot enter the light transmissionarea, thereby further improving accuracy of the measurement of the cellthickness. Moreover, due to the arrangement of the annular barrier 500,the waste of the liquid crystal is avoided, thereby further reducing themanufacturing cost.

In another embodiment, the barrier 500 and the first frame sealingstructure 400 are made of the same material. The barrier 500 and thefirst frame sealing structure 400 have the same function. Therefore, thesame material can be used, which enables the barrier 500 and the firstframe sealing structure 400 to be formed in the same manufacturingprocess, avoiding increasing production costs and manufacturingprocesses. In an exemplary embodiment, the barrier 500 and the firstframe sealing structure 400 are made of a frame sealant material andformed by a coating and curing process.

It should be noted that in FIGS. 19 and 20, the first substrate 100 andthe second substrate 200 are continuous structures, and because theliquid crystal layer 300 is made of a transparent material, light canpass through the liquid crystal cell during measuring the cellthickness. However, the embodiment of the present application is notlimited to this. In an embodiment, referring to FIG. 22, the firstsubstrate 100 and the second substrate 200 may also be hollow-outareaed-out structures. The hollow-out areaed-out structures of the firstsubstrate 100 and the second substrate 200 correspond to the thirdhollow-out area 215 of the second metal electrode 211, that is,coincident with the sandwiched area 213 formed between the firsttransmission area T1 and the second transmission area T2. In anexemplary embodiment, the hollow-out areaed-out structure of the firstsubstrate 100 is a first through hole h1, the hollow-out areaed-outstructure of the second substrate 200 is a second through hole h2. Thefirst through hole h1 overlaps with a vertical projection of the secondthrough hole h2 on the first substrate 100, the first through hole h1 isoverlapped with a vertical projection of the third hollow-out area 215on the first substrate 100, and the second through hole h2 is overlappedwith a vertical projection of the third hollow-out area 215 on thesecond substrate 200.

In an embodiment, the first through hole h1 of the first substrate 100and the second through hole h2 of the second substrate 200 may befabricated after the liquid crystal cell is formed. In an exemplaryembodiment, a barrier is formed between the first substrate 100 and thesecond substrate 200, and after the liquid crystal cell is formed, anarea provided with the barrier is perforated, and part of the firstsubstrate 100, part of the second substrate 200 and part of the barrierare removed, thereby forming the hollow-out areaed-out structures of thefirst substrate 100 and the second substrate 200, and the annularbarrier 500.

In an embodiment, please refer to FIG. 23, the liquid crystal antennaprovided by the embodiment of the present application further includes afixed device 1000, and a fixed rod 600 penetrates through the firstthrough hole h1 and the second through hole h2 and is connected to thefixed device 1000. The fixed device 1000 is provided with a groovecapable of accommodating the fixed rod 600, and the fixed rod 600 isprovided with a fixed structure at a connection position with thegroove. In an exemplary embodiment, the fixed rod 600 may be providedwith a thread at the connection position with the groove, and the grooveof the fixed device is also internally provided with a thread matchingthe fixed rod 600. The liquid crystal antenna needs to be fixed on otherdevices during use. Therefore, the liquid crystal antenna is fixed toother devices through adhesive glue, or a card slot is provided on otherdevices to place the liquid crystal antenna. While, in the presentembodiment, the first through hole h1 and the second through hole h2formed by a perforating method can not only realize the cell thicknesstest of the liquid crystal cell but also be used to place the fixed rod600 to achieve fixation with other devices.

In an embodiment, the liquid crystal layer 300 is made of polymer liquidcrystal, and the barrier 500 is formed by polymers in the polymer liquidcrystal. In an exemplary embodiment, the polymer liquid crystal is thata polymer monomer is added to the liquid crystal molecule, and after theliquid crystal cell is formed, ultraviolet light is used to irradiatefrom one side of the second substrate 200, then the polymer monomerswithin an area irradiated by the ultraviolet light polymerize to formthe barrier 500. Finally, a perforating process is used to form thestructure illustrated in FIG. 22. In the present embodiment, comparedwith the process for manufacturing the liquid crystal antenna in therelated art, it is merely necessary to add a step of ultravioletirradiation and a step of perforation, without setting a separatemanufacturing step for the barrier. It is important that one side of thesecond substrate 200 corresponding to an interior of the liquid crystalcell is opaque except for a position of the third hollow-out area 215.

Therefore, so as long as light is incident from one side of the secondsubstrate 200, the barrier 500 can be formed at the position of thethird hollow-out area 215 without arranging the mask plate, that is,production of the annular barrier 500 does not need the mask plate,thereby saving the production cost.

With continued reference to FIG. 24, in order to clearly illustrateposition relationships between the first hollow-out area 212, the thirdhollow-out area 215 and the microstrip line unit 113, some necessarystructures are omitted in the figure. As illustrated in FIG. 24, aminimum distance between the third hollow-out area 215 and themicrostrip line unit 113 is L1, and L1≥200 μm. The third hollow-out area215 is formed by patterning and by etching the second metal electrode211. The second metal electrode 211 is used to prevent a signal in theliquid crystal cell from leaking outward, and a signal transmitted bythe microstrip line unit 113 can be prevented from leaking outwardthrough the third hollow-out area 215 by controlling the minimumdistance L1 between the third hollow-out area 215 and the microstripline unit 113.

In an embodiment, with continued reference to FIG. 24, a minimumdistance between the third hollow-out area 215 and the first hollow-outarea 212 is L2, and L2≥200 μm. The first hollow-out area 212 is ahollow-out area of the second metal electrode 211. The signal of themicrostrip line unit 113 can be coupled to the third metal electrode 222through the first hollow-out area 212, and the third metal electrode 222radiates the signal outward. The signal that should have been coupledfrom the first hollow-out area 212 to the third metal electrode 22 isavoided from leaking from the third hollow-out area 215 by increasingthe distance between the third hollow-out area 215 and the firsthollow-out area 212, thereby avoiding reducing the performance of theliquid crystal antenna.

In an embodiment, please refer to FIGS. 18 and 25, the liquid crystalantenna further includes the signal introduction area of the secondsubstrate 200 beyond the first substrate 100, and the signalintroduction area includes the through hole running through the secondsubstrate 200. The second metal electrode 211 is provided with thesecond hollow-out area 214 within the signal introduction area, and thethrough hole is located within the second hollow-out area 214. Thesignal introduction rod 240 penetrates through the through hole. Thesignal introduction rod 240 is used to provide the high frequency signalto the liquid crystal antenna, and the high frequency signal istransmitted through a feeder electrode and coupled to the microstripline unit 113. It should be noted that a section of FIG. 18 at KK′ and asection of FIG. 4 at EE′ have a same structure. Therefore, structuresillustrated in FIGS. 9 and 25 are the same.

In an embodiment, with reference to FIG. 26, the liquid crystal antennafurther includes a flexible circuit board 140, and the flexible circuitboard 140 is bindingly connected to the driving circuit 130. Theflexible circuit board 140 is a medium for connecting the liquid crystalantenna with an external circuit. The flexible circuit board 140 iscapable of transmitting a signal source to the liquid crystal antennathrough the external circuit, and rotation of the liquid crystal can beadjusted by controlling the signal source, thereby controlling aradiation direction and radiation amount of the signal.

In FIGS. 18 to 25, in order to clearly illustrate position relationshipsbetween the first metal electrode 111, the second metal electrode 211,the third metal electrode 222, and each hollow-out area arranged on thesecond metal electrode 211, part of the structure has not yet beenillustrated. However, the liquid crystal antenna provided by theembodiment of the present application still includes necessarystructures for realizing the function of the antenna.

In an embodiment, please further refer to FIG. 26, the first substrate100 is further provided with the wires 114 for connecting the respectivebinding pads 112 with the respective microstrip line units 113. Thewires 114 connected to the respective microstrip line units 113 areinsulated from each other and connected to the different binding pads112. The second substrate 200 is provided with the feeder line 241electrically connected to the signal introduction rod 240. The feederline 241 is distributed in the dendritic shape and includes a pluralityof branches, and the vertical projection of one branch of the feederline 241 on the second baseplate 200 partially overlaps with thevertical projection of one microstrip line unit 113 on the secondbaseplate 200. The feeder line 241 couples the high frequency signal ofthe signal introduction rod 240 to the microstrip line unit 113, and thesignal transmitted in the microstrip line unit 113 is controlled bycontrolling deflection of the liquid crystal layer 300. Finally, thesignal is coupled to the third metal electrode 222 at the firsthollow-out area 212 of the second metal electrode 211, and the thirdmetal electrode 222 radiates the signal outward. It should be noted thatthe third metal electrode 222 is a plurality of radiator unitsindependent from each other, and each radiator unit radiates signalsoutward.

As illustrated in FIG. 26, the first hollow-out area 212 includes afirst division 212 a, and a vertical projection of the first division212 a on the second substrate 200 is overlapped with the verticalprojections of the feeder line 241 and a second division 212 b on thesecond substrate 200. At a position of the first division 212 a, thefeeder line 241 couples the high frequency signal to the microstrip lineunit 113. At a position of the second division 212 b, the microstripline unit 113 couples the signal to the third metal electrode 222.Finally, the signal is radiated outward from the third metal electrode222.

A shape of the third hollow-out area 215 is not limited to the rectangleshape shown in FIG. 26, but also includes other shapes, such as the ovalor circular shape shown in FIG. 27, or the triangle shape shown in FIG.28. Apparently, the third hollow-out area 215 can also be a polygon ofother shapes and can be reused as the alignment mark, for example, thethird hollow-out area 215 can be cross-shaped like the sandwiched area213 shown in FIG. 17.

In an embodiment, as illustrated in FIG. 29, the driving circuit 130includes the binding pad 112, the binding pad 112 includes an input pad112 b and an output pad 112 a, and the output pad 112 b is connected tothe flexible circuit board 140. When application of liquid crystalantenna is more extensive, more liquid crystal antenna units are needed,while it is also necessary to maintain lightness, thinness andminiaturization. Therefore, structures of other non-liquid crystal unitsshould not take up too much space. In order to further reduce a framebinding on one side of the driving circuit 130, the output pads 112 a onboth sides of the driving circuit 130 are sunk to one side of the inputpads 112 b.

It should be noted that in the above embodiment, when an overlappinglight transmission area is arranged on the first substrate 100 and thesecond substrate 200 in the liquid crystal cell, in order to preventleakage of the high frequency signals, it is necessary to maintain acertain distance between the light transmission area and a functionalarea of the liquid crystal antenna. The functional area of the liquidcrystal antenna includes the microstrip line unit, the feeder line and aradiation electrode. In order to further improve an amount of radiationsignals of the liquid crystal antenna, a transparent conductorelectrically connected to a corresponding metal electrode can bearranged within the light transmission area. In an embodiment, atransparent conductor, such as transparent indium tin oxide, is arrangedwithin the second transparent area T2. The transparent conductor iselectrically connected to the second metal electrode 211. In anotherembodiment, a whole surface of indium tin oxide is firstly arranged onthe second substrate 200, and then the metal film layer is deposited,the second metal electrode 211 and each hollow-out area are obtained bypatterning the metal film layer, and the metal film layer at theposition of the second light transmission area T2 is etched out. In thepresent embodiment, the indium tin oxide in the second lighttransmission area T2 can replace a function of the ground electrode (thesecond metal electrode) in the related art, thereby preventing signalleakage.

On the other aspect, further provided is a communication device,including the liquid crystal antenna of any one of the aboveembodiments. Referring to FIG. 30, the communication device includes aliquid crystal antenna 1000 and a housing 1100 for accommodating theliquid crystal antenna 1000. The communication device can be placedinside a car so that the car can receive a signal.

Further provided is a manufacturing method for the liquid crystalantenna. In an embodiment, please refer to FIGS. 31 to 35. Themanufacturing method for the liquid crystal antenna provided by theembodiment of the present application is described as follows.

In step S11, the first substrate 100 and the second substrate 200 areprovided, and the first metal electrode 111, the line connected to thedriving circuit and the first light transmission area are formed on thefirst substrate 100. The first metal electrode 111 includes a pluralityof microstrip line units 113, and the line connected to the drivingcircuit includes the binding pad 112. It should be noted that, on thefirst substrate 100, an area without the first metal electrode 111 andthe line connected to the driving circuit can be used as the first lighttransmission area.

In step S12, the second metal electrode 211 are formed on one side ofthe second substrate 200 and a second light transmission area T2 isformed within an area of the second substrate 200 beyond the first framesealing structure 400, and the second metal electrode 211 includes aplurality of first hollow-out areas 212. The second metal electrode 211is formed, meanwhile, the first hollow-out area 212, the secondhollow-out area 214 and the second light transmission area T2 areformed. The second metal electrode 211 needs to be hollow-out areaed outat the position of the second light transmission area T2.

In step S13, the third metal electrode 222 is formed on another side ofthe second substrate 200. The vertical projection of the firsthollow-out area 212 on the second substrate 200 is located within thevertical projection of the third metal electrode 222 on the secondsubstrate 200, and the vertical projection of the third metal electrode222 on the second baseplate 200 is not overlapped with the second lighttransmission area T2. It should be noted that the third metal electrode222 is formed, meanwhile, the feeder line 241 is formed, that is, thethird metal electrode 222 and the feeder line 241 are located in a samemetal layer, and the third metal electrode 222 and the feeder line 241are formed simultaneously through the same process. The first hollow-outarea 212 formed in step S12 includes the first division 212 a, thevertical projection of the first division 212 a on the second substrate200 is overlapped with the vertical projections of the feeder line 241and the second division 212 b on the second substrate 200. At theposition of the first division 212 a, the feeder line 241 couples thehigh frequency signal to the microstrip line unit 113. At the positionof the second division 212 b, the microstrip line unit 113 couples thesignal to the third metal electrode 222. Finally, the signal is radiatedoutward from the third metal electrode 222.

In step S14, the first substrate 100 formed with the first metalelectrode 111, the line connected to the driving circuit and the firstlight transmission area T1, and the second substrate 200 formed with thesecond metal electrode 211, the second light transmission area T2 andthe third metal electrode 222 are aligned into a cell to form the liquidcrystal cell, so that the first frame sealing structure 400 and theliquid crystal layer are arranged between the first substrate 100 andthe second substrate 200, the first frame sealing structure 400 isarranged around the liquid crystal layer, and a vertical projection ofthe first light transmission area T1 is overlapped with a verticalprojection of the second light transmission area T2.

In step S15, the second substrate 200 is cut, so that the firstsubstrate 100 exposes the line connected to the driving circuit. Thedriving circuit 130 is electrically connected to a connecting line.

It should be noted that FIGS. 32 to 35 illustrate a formation process ofa single liquid crystal antenna. In an actual production process, inorder to improve production efficiency, a plurality of liquid crystalantennas are usually produced through one production process. In anembodiment, please see FIG. 36, in step S11, a plurality of units areformed on a large substrate (a large piece of substrate), and each unitincludes the structure as shown in FIG. 32. In an exemplary embodiment,the large piece of substrate includes 4 units: a first unit U1, a secondunit U2, a third unit U3, and a fourth unit U4. Each unit is providedwith a microstrip line unit, a connecting line and a binding terminal.In step S12, similarly, a plurality of units are formed on a largesubstrate (a large piece of substrate), and each unit includes thestructure as shown in FIG. 33, for example, the first unit U1, thesecond unit U2, the third unit U3, and the fourth unit U4. In step S13,a plurality of structures corresponding to FIG. 34 are formed on theother side of the large piece of substrate used in step S12, that is,structures as shown in FIG. 34 are formed at positions of the first unitU1, the second unit U2, the third unit U3 and the fourth unit U4. Instep S14, after two large pieces of substrate are aligned into a cell, aplurality of liquid crystal cells are formed, and the plurality ofliquid crystal cells correspond to the first unit U1, the second unitU2, the third unit U3 and the fourth unit U4, respectively. When thelarge piece of substrate is used for manufacture, the large piece ofsubstrate after aligned into a cell needs to be cut to obtain a singleliquid crystal antenna before step S15. In another exemplary embodiment,the liquid crystal cells corresponding to the first unit U1, the secondunit U2, the third unit U3 and the fourth unit U4 are cut and separated.Therefore, step S15 is to cut a single liquid crystal cell so as toexpose the line connected to the driving circuit.

In an embodiment, further provided is another manufacturing method forthe liquid crystal antenna. Please refer to FIGS. 32 to 37, themanufacturing method for the liquid crystal antenna includes thefollowing steps.

In step S21, the first substrate 100, the second substrate 200 and thethird substrate 200′ are provided, and the first metal electrode 111,the line connected to the driving circuit and the first lighttransmission area T1 are formed on the first substrate 100. The firstmetal electrode 111 includes a plurality of microstrip line units 113.

In step S22, the second metal electrode 211 is formed on one side of thesecond substrate 200 and a second light transmission area T2 is formedwithin an area of the second substrate 200 beyond the first framesealing structure 400, and the second metal electrode 211 includes aplurality of first hollow-out areas 212. The second metal electrode 211is formed, meanwhile, the first hollow-out area 212, the secondhollow-out area 214 and the second light transmission area T2 areformed, and the second metal electrode 211 needs to be hollow-out areaedout at the position of the second light transmission area T2.

In step S23, the third metal electrode 222 is formed on one side of thethird substrate 200′. It should be noted that the third metal electrode222 is formed, meanwhile, the feeder line 241 is formed, that is, thethird metal electrode 222 and the feeder line 241 are located in a samemetal layer, and the third metal electrode 222 and the feeder line 241are formed simultaneously through a same process. The first hollow-outarea 212 includes the first division 212 a and the second division 212b, the vertical projections of the first division 212 a and the seconddivision 212 b on the second substrate 200 is overlapped with thevertical projection of the feeder line 241 on the second substrate 200.At the position of the first division 212 a, the feeder line 241 couplesthe high frequency signal to the microstrip line unit 113. At theposition of the second division 212 b, the microstrip line unit 113couples the signal to the third metal electrode 222. Finally, the signalis radiated outward from the third metal electrode 222.

In step S24, the first substrate 100 formed with the first metalelectrode 111, the line connected to the driving circuit and the firstlight transmission area T1, and the second substrate 200 formed with thesecond metal electrode 211 and the second light transmission area T2 arealigned into a cell to form the liquid crystal cell, so that the firstframe sealing structure 400 and the liquid crystal layer are arrangedbetween the first substrate 100 and the second substrate 200, the firstframe sealing structure 400 is arranged around the liquid crystal layer,and the vertical projection of the first light transmission area T1 isoverlapped with the vertical projection of the second light transmissionarea T2.

In step S25, the second substrate 200 is cut, so that the firstsubstrate 100 exposes the line connected to the driving circuit.

In step S26, the third substrate 200′ formed with the third metalelectrode 222 is aligned to get fitted with the liquid crystal cellformed in step S24, so that an area of the third substrate 200′overlapped with the vertical projection of the first light transmissionarea T1 on the third substrate 200′ and an area of the third substrate200′ overlapped with the vertical projection of the second lighttransmission area T2 on the third substrate 200′ are light transmissive.

Similarly, in the manufacturing method for the liquid crystal antenna,the large piece of substrate can also be used for manufacturing. Whenthe large piece of substrate is used for manufacturing the liquidcrystal antenna, the liquid crystal cell formed in step S24 needs to becut to form a single liquid crystal cell before step S25.

It needs to be further explained that in the method of manufacturing theliquid crystal antenna through the large piece of substrate, an order ofsteps S24 to S26 needs to be adjusted. In an embodiment, step S26 needsto be performed before step S24, the liquid crystal celles formed bythree large pieces of substrates are first cut to form a single liquidcrystal antenna, and then the second substrate 200 and the thirdsubstrate 200′ are cut to expose the line connected to the drivingcircuit on the first substrate 100.

In the two types of manufacturing methods provided above, the methodsfurther include binding the driving circuit 130 to the liquid crystalantenna cell. The driving circuit 130 is used for providing signals tothe liquid crystal antenna. When the first substrate 100 and the secondsubstrate 200 are aligned into a cell, a first frame sealing structure400 needs to be formed. At the same time, the second frame sealingstructure 401 is formed in a same process. The second frame sealingstructure 401 surrounds the sandwiched area formed between the firstlight transmission area T1 and the second light transmission area T2.

In an embodiment, further provided is another manufacturing method forthe liquid crystal antenna. Please refer to FIGS. 38 to 42, themanufacturing method includes the following steps.

In step S31, the first substrate 100 and the second substrate 200 areprovided, and the first metal electrode 111 and the line connected tothe driving circuit are formed on the first substrate 100. The firstmetal electrode 111 includes a plurality of microstrip line units 113,the line connected to the driving circuit includes the binding pad 112and the wire 114 for connecting the binding pad 112 with the microstripline unit 113.

In step S32, the second metal electrode 211 is formed on one side of thesecond substrate 200, and the second metal electrode 211 includes aplurality of first hollow-out areas 212 and at least one thirdhollow-out area 215. It should be noted that the first hollow-out area212 and the third hollow-out area 215 are formed, meanwhile, the secondhollow-out area 214 is formed; the second hollow-out area 214 iscorrespondingly provided with the signal introduction rod 240, and thethird hollow-out area 215 corresponds to the second light transmissionarea T2.

In step S33, the third metal electrode 222 is formed on another side ofthe second substrate 200, the vertical projection of the firsthollow-out area 212 on the second substrate 200 is located within thevertical projection of the third metal electrode 222 on the secondsubstrate 200, and the vertical projection of the third metal electrode222 on the second substrate 200 is not overlapped with the verticalprojection of the third hollow-out area 215 on the second substrate 200.It should be noted that the third metal electrode 222 is formed,meanwhile, the feeder line 241 is formed, that is, the third metalelectrode 222 and the feeder line 241 are located in a same metal layer,and the third metal electrode 222 and the feeder line 241 are formedsimultaneously through the same process. The first hollow-out area 212includes the first division 212 a, the vertical projection of the firstdivision 212 a is overlapped with the vertical projections of the feederline 241 and the second division 212 b on the second substrate 200. Atthe position of the first division 212 a, the feeder line 241 couplesthe high frequency signal to the microstrip line unit 113. At theposition of the second division 212 b, the microstrip line unit 113couples the signal to the third metal electrode 222. Finally, the signalis radiated outward from the third metal electrode 222.

In step S34, the first substrate 100 formed with the first metalelectrode 111 and the line connected to the driving circuit, and thesecond substrate 200 formed with the second metal electrode 211 and thethird metal electrode 222 are aligned into a cell to form the liquidcrystal cell, so that the first frame sealing structure 400 and theliquid crystal layer are arranged between the first substrate 100 andthe second substrate 200, the first frame sealing structure 400 isarranged around the liquid crystal layer, and the vertical projection ofthe third hollow-out area 215 on the first substrate 100 is notoverlapped with the vertical projection of the first metal electrode 111on the first substrate 100.

In step S35, the second substrate 200 is cut, so that the firstsubstrate 100 exposes the line connected to the driving circuit.

Similarly, in the present embodiment, in order to improve productionefficiency, a large piece of substrate can also be used formanufacturing, and a manufacturing method thereof is similar to themethod of using the large piece of substrate in the above twoembodiments, and will not be repeated here. In an embodiment, after stepS35, a step of binding the driving circuit 130 is further included. Andin another embodiment, a step of binding the flexible circuit board 140is further included. The flexible circuit board 140 and the drivingcircuit are electrically connected through the binding pad 112 on thefirst substrate.

In the present embodiment, after step S35, in addition to binding thedriving circuit 130 and the flexible circuit board 140, a step ofperforating the liquid crystal cell and a step of perforating at thesandwiched area 213 formed between the first light transmission area T1and the second light transmission area T1 are further included. Itshould be noted that before aligning the first substrate 100 and thesecond substrate 200 into a cell, the barrier needs to be formed so asto prevent liquid crystal leakage after perforating the liquid crystalcell.

In an embodiment, the barrier can be formed simultaneously with thefirst frame sealing structure 400. However, the embodiment of thepresent application is not limited to this. In an embodiment, thepolymer monomer may be added to the liquid crystal layer. After theliquid crystal cell is formed, the ultraviolet light is used toirradiate from one side of the second substrate 200, and the polymermonomers within an area irradiated by the ultraviolet light polymerizeto form the barrier 500. Finally, a perforating process is used to formthe structure illustrated in FIG. 22. In the step in which the polymermonomer within the area irradiated by the ultraviolet light polymerizeto form the barrier 500, the mask plate may be used to form the barrier500 within a particular light transmission area. However, because in theliquid crystal antenna, each metal electrode is opaque, a functionalarea of the liquid crystal antenna is shield by the metal, the lightcannot pass through and thus cannot cause the polymer monomer to formthe barrier within the functional area of the liquid crystal antenna.Therefore, the mask plate may also not be used, which avoids increasingthe production cost.

In another embodiment, in order to facilitate perforating, a perforatingmark may be set in advance on one side of the first substrate 100 facingaway from the second substrate 200, or on one side of the secondsubstrate 200 facing away from the first substrate 100. As shown in FIG.42, the perforating mark may be an oval structure or a circularstructure.

In the manufacturing methods for each of the liquid crystal antennasdescribed above, a step in which the first substrate 100 is cut toexpose the second hollow-out area 214 of the second substrate is furtherincluded, thereby facilitating perforating the second substrate 200 toconnect the signal introduction rod 240 to the liquid crystal antenna.The signal introduction rod 240 is electrically connected to the feederline 241, thereby introducing the high frequency signal into the liquidcrystal antenna. The high frequency signal is coupled to the microstripline unit 113 on the first substrate 100 through the feeder line 241 atthe first division 212 a of the first hollow-out area 212. Themicrostrip line unit 113 is coupled to the third metal electrode 222through the liquid crystal layer at the second division 212 b of thefirst hollow-out area 212, and the third metal electrode 222 radiatesthe signal outward.

It should be noted that in the liquid crystal antenna and themanufacturing method for the liquid crystal antenna provided by theembodiment of the present application, within an area where the cellthickness is tested, the first metal electrode 111, the second metalelectrode 211 and the third metal electrode 222 each are designed to behollow-out areaed-out. That is, the first metal electrode 111, thesecond metal electrode 211 and the third metal electrode 222 each areformed by a film forming and patterning process, then each metal filmlayer within the area where the cell thickness is tested is etched outin the patterning process.

It should be further noted that in the liquid crystal antenna providedby the embodiment of the present application, merely the driving circuit130 or the flexible circuit board 140 may be included, or both thedriving circuit 130 and the flexible circuit board 140 may be included.A specific design needs to be determined according to an actualsituation. The driving circuit 130 may be the driving chip (integratedcircuit, IC). The driving chip may be connected to each part of theliquid crystal antenna by directly binding on the substrate, or bypre-binding to an intermediate substrate, and then through bindingconnection between the intermediate substrate and the substrate torealize chain connection to each part of the liquid crystal antenna. Inan embodiment, the intermediate substrate may be a flexible substrate.

Because the liquid crystal antenna and manufacturing method thereof andthe communication device provided by the embodiment of the presentapplication are provided with a light transmission area used to test thecell thickness, the cell thickness can be measured at initial formationof the cell, and according to the pressure of the pressure head matchedwith measured data, more liquid crystal antennas can meet a requiredrange of cell thickness determined by other parameters, therebyimproving a mass production yield of the liquid crystal antennas, whichprovides a basis for mass application of the liquid crystal antennas.

The above description of the disclosed embodiments enables those skilledin the art to implement or use the present invention. Variousmodifications to these embodiments will be apparent to those skilled inthe art, and the general principles defined herein may be implemented inother embodiments without departing from the spirit or scope of thepresent invention. Therefore, the present invention is not intended tobe limited to the embodiments shown herein but is to be accorded thewidest scope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A liquid crystal antenna, comprising: a firstsubstrate; a second substrate arranged opposite to the first substrate;a liquid crystal layer located between the first substrate and thesecond substrate; a first metal electrode located on one side of thefirst substrate facing toward the second substrate, wherein the firstmetal electrode comprises a plurality of microstrip line units; adriving circuit located within a step area of the first substrate beyondthe second substrate, wherein the first metal electrode is electricallyconnected to the driving circuit; a second metal electrode located onone side of the second substrate facing toward the first substrate,wherein the second metal electrode comprises a plurality of firsthollow-out areas, and a vertical projection of one of the plurality offirst hollow-out areas on the second substrate is located within avertical projection of the first metal electrode on the secondsubstrate; a third metal electrode located on one side of the secondsubstrate facing away from the first substrate, wherein the verticalprojection of the one of the plurality of first hollow-out areas on thesecond substrate is located within a vertical projection of the thirdmetal electrode on the second substrate; and a first frame sealingstructure located between the first substrate and the second substrateand arranged around the liquid crystal layer, wherein the firstsubstrate, and the second substrate and the first frame sealingstructure form a liquid crystal cell; wherein, the first substrate andthe second substrate each are a transparent substrate; the firstsubstrate comprises a first extension area beyond the first framesealing structure, the first extension area comprises a first lighttransmission area, and a first transparent film layer or no structure isarranged within the first light transmission area; the second substratecomprises a second extension area beyond the first frame sealingstructure, the second extension area comprises a second lighttransmission area, and a second transparent film layer or no structureis arranged within the second light transmission area; and the firstlight transmission area is overlapped with the second light transmissionarea.
 2. The liquid crystal antenna according to claim 1, furthercomprising a second frame sealing structure, wherein the second framesealing structure is located on one side of the first frame sealingstructure, and the first substrate, the second substrate, the firstsealing structure and the second frame sealing structure form anextension cell.
 3. The liquid crystal antenna according to claim 2,wherein the first frame sealing structure and the second frame sealingstructure each are frame sealant.
 4. The liquid crystal antennaaccording to claim 2, wherein the first frame sealing structure is framesealant, and the second frame sealing structure is a supportingretaining wall.
 5. The liquid crystal antenna according to claim 1,wherein the first light transmission area and the step area are locatedon a same side of the liquid crystal cell.
 6. The liquid crystal antennaaccording to claim 1, further comprising a signal introduction area ofthe second substrate beyond the first substrate, wherein the secondmetal electrode further comprises a second hollow-out area, and thesignal introduction area is located within the second hollow-out area;and a through hole running through the second substrate is arranged inthe signal introduction area.
 7. The liquid crystal antenna according toclaim 6, wherein the signal introduction area and the step area areseparately located on both sides of the liquid crystal cell and areoppositely arranged.
 8. The liquid crystal antenna according to claim 6,wherein the second light transmission area and the signal introductionarea are located on a same side of the liquid crystal cell.
 9. Theliquid crystal antenna according to claim 1, wherein the driving circuitis a flexible circuit board.
 10. The liquid crystal antenna according toclaim 1, further comprising a third substrate, wherein the thirdsubstrate is located on one side of the second substrate facing awayfrom the first substrate, the third metal electrode is located on oneside of the third substrate facing away from the second substrate, andan area of the third substrate overlapped with the first lighttransmission area and second light transmission area is lighttransmissive.
 11. A liquid crystal antenna, comprising: a firstsubstrate; a second substrate arranged opposite to the first substrate;a liquid crystal layer located between the first substrate and thesecond substrate; a first frame sealing structure located between thefirst substrate and the second substrate and arranged around the liquidcrystal layer, wherein the first substrate, the second substrate and thefirst frame sealing structure form a liquid crystal cell; a first metalelectrode located on one side of the first substrate facing toward thesecond substrate, wherein the first metal electrode comprises aplurality of microstrip line units; a driving circuit located within astep area of the first substrate beyond the second substrate, whereinthe first metal electrode is electrically connected to the drivingcircuit; a second metal electrode located on one side of the secondsubstrate facing toward the first substrate, wherein the second metalelectrode comprises a plurality of first hollow-out areas and at leastone third hollow-out area, and a vertical projection of one of theplurality of first hollow-out areas on the second substrate is locatedwithin a vertical projection of the first metal electrode on the secondsubstrate; and a third metal electrode located on one side of the secondsubstrate facing away from the first substrate, wherein the verticalprojection of the one of the plurality of first hollow-out areas on thesecond substrate is located within a vertical projection of the thirdmetal electrode on the second substrate; wherein, the at least one thirdhollow-out area is not overlapped with neither the first metal electrodenor the third metal electrode; and the vertical projection of the one ofthe plurality of first hollow-out areas and a vertical projection of theat least one third hollow-out area on the second substrate are locatedwithin a vertical projection of the liquid crystal cell on the secondsubstrate.
 12. The liquid crystal antenna according to claim 11, furthercomprising an annular barrier located in the liquid crystal layer,wherein an area surrounded by the annular barrier is overlapped with theat least one third hollow-out area.
 13. The liquid crystal antennaaccording to claim 12, wherein the annular barrier and the first framesealing structure are made of the same material.
 14. The liquid crystalantenna according to claim 12, wherein the liquid crystal layer is madeof polymer liquid crystal, and the annular barrier is made of polymersin the polymer liquid crystal.
 15. The liquid crystal antenna accordingto claim 11, wherein a minimum distance between the at least one thirdhollow-out area and one of the plurality of microstrip line units is L1,and L1≥200 μm.
 16. The liquid crystal antenna according to claim 11,wherein a minimum distance between the at least one third hollow-outarea and the one of the plurality of first hollow-out areas is L2, andL2≥200 μm.
 17. The liquid crystal antenna according to claim 11, whereinthe first substrate comprises a first through hole, the second substratecomprises a second through hole, wherein the first through hole isoverlapped with the second through hole, the first through hole isoverlapped with the at least one third hollow-out area, and the secondthrough hole is overlapped with the at least one third hollow-out area.18. The liquid crystal antenna according to claim 11, further comprisinga fixed device, wherein a fixed rod penetrates through the first throughhole and the second through hole, and is connected to the fixed device.19. The liquid crystal antenna according to claim 11, further comprisinga signal introduction area of the second substrate beyond the firstsubstrate, wherein the signal introduction area comprises a through holerunning through the second substrate.
 20. A communication device,further comprising a liquid crystal antenna, wherein the liquid crystalantenna comprises: a first substrate; a second substrate arrangedopposite to the first substrate; a liquid crystal layer located betweenthe first substrate and the second substrate; a first frame sealingstructure located between the first substrate and the second substrateand arranged around the liquid crystal layer, wherein the firstsubstrate, the second substrate and the first frame sealing structureform a liquid crystal cell; a first metal electrode located on one sideof the first substrate facing toward the second substrate, wherein thefirst metal electrode comprises a plurality of microstrip line units; adriving circuit located within a step area of the first substrate beyondthe second substrate, wherein the first metal electrode is electricallyconnected to the driving circuit; a second metal electrode located onone side of the second substrate facing toward the first substrate,wherein the second metal electrode comprises a plurality of firsthollow-out areas and at least one third hollow-out area, and a verticalprojection of one of the plurality of first hollow-out areas on thesecond substrate is located within a vertical projection of the firstmetal electrode on the second substrate; and a third metal electrodelocated on one side of the second substrate facing away from the firstsubstrate, wherein the vertical projection of the one of the pluralityof first hollow-out areas on the second substrate is located within avertical projection of the third metal electrode on the secondsubstrate; wherein, the at least one third hollow-out area is notoverlapped with neither the first metal electrode nor the third metalelectrode; and the vertical projection of the one of the plurality offirst hollow-out areas and a vertical projection of the at least onethird hollow-out area on the second substrate are located within avertical projection of the liquid crystal cell on the second substrate.